Brammo Enertia Discussion > Brammo Enertia Plus

Charging Q

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seanmcp:
Electrical Engineering Background here so I'll ask nerdy questions hopefully someone has real technical data for:

What are the peak & sustained current draws during a recharge of the Plus from as close to empty as the cells get when charging with the stock (onboard) charger? Please provide data for both 200-240V single phase 2-pole (a dryer-style plug which I see mentioned as supported) and 120V single phase single pole standard household lighting circuits (commonly 15A max, with 12A usable sustained max).

I ask as I'm trying to see if I can induce coworkers here into these units, and if so, I'd need to build my own charging rig(s). I manage several facilities with capacities in the MW range each, so a few kWh here and there isn't an issue, but I do need to plan accordingly for the charging station layout and being able to quantify the numbers for an accounting standpoint.

Currently (no pun intended), since I haven't seen any real data, I'm basing my scratched notes on an 800-900W charger which'd be the 'right' size for a unit to both handle peak draw for that size of pack and provide enough juice to 'finish it' in ~8 hours. The good thing (well, one of many) about LiIons are they accept charge better than old Lead Acid cells with less loss. A good 90+% load-side efficient 850 watt unit could push right at 6 kWh into a cell in 8 hours if it could do it in a perfectly flat supply, but sadly, the real world is messier than that. Luckily, 12A @ 115V nominal = 1.38 kW so there's plenty of 'slack' on a 15A lighting circuit to handle the initial part of the charge curve. I know, the engineers there did all this math before, but I wondered how 'close' they came to the line and how long they 'stay there'. UL listing means I don't have anything to worry about, obviously, from a safety perspective, but I do have to figure out what my load profiles for multiple guys charging up in the AM will look like, and that's the curve I am missing ATM.

That said, few things are more fun than being an electrical geek and finally feeling like it's the right time to buy a VERY practical electric motorcycle! Thanks, Brammo :)

HighlanderMWC:
Unless somebody from Brammo speaks up you're not going to be able to get that info as there aren't any of these "in the wild".

From an Enertia standpoint only 120V is supported (stock at least) and the display indicates 8-9amp draw and an estimated charging time (on the display) of about 3 hours (from 10% remaining). My Kill-A-Watt typically shows around 3.2 kwh for that.

Hope some of that is useful to you.

Gavin:
Supposedly the Empulse also supports Level 2 charging...I wonder if the Enertia Plus will have that as an option.

Right now there isn't much level two charging available, but that will change fairly fast. I plan to install level two charging in my garage this Janaury if I get my LEAF, or if I cancel the LEAF, at least before I get the Fiat 500 EV in 2012 (which is the car I really want).

Not at all a deal breaker...the Enertia doesn't NEED level 2 charging to be a wonderful commuter. But I imagine that future versions likely will support level 2 charging, and it would be a welcome add on if Brammo made it available to the current model coming in the Spring.

Gavin

seanmcp:
Is the 8-9A sustained w/o a drop for the duration of the charge, except the tail off? That's 960-1080W from the plug to the input side of the charger, so with decent efficiency that's 875-975W to the cell. 8 hours @ 875W would be 7kWh of total output juice from the charger, and the LiIons accept charge pretty readily VS lead acid. It's just hard to know w/o having my own meter on one or someone reporting what their killawatt says hour by hour if there's an initial hard charge at say 1000W from the charger which drops over time evenly, or if it's more varied. I'm enough of a nerd I'd happily walk by my killawatt every 15 minutes for 8 hours and record current draw (well, I'd use one of my logging meters and let it do the work, but you know what I mean *grin*).

One of the news articles today about the Plus mentioned 120 & 220V charging (they mentioned 4 hour charges using a dryer outlet, as their analogy, but media tends to have the least technical view on things), which made me hope for the 220 ability to be onboard. Added complexity, sure, but I was hopeful. The majority only mention the standard charging circuit, so I'll assume I'm stuck with low and slow. That's just fine if I build a charging location for multiple folks, as I'll just hang a small subpanel worth of feeds in a parking area for them and spend a few bucks painting 'Employee EV Parking' on the concrete pad :)

HighlanderMWC:
The few times I've checked on it during the main charging cycle it has been the same draw. It would seem to need to be that much continuously in order to draw 3kwh in 3 hours. After the main charge it will go into "balancing mode" which according to Brammo draws about 50w.

I wouldn't be surprised if the Enertia Plus (or the Empulse) can charge off either 220v or 110v. Going from 8 to 4 hours would have a lot more benefit to sales/marketing than going from 3 to 1.5 hours, plus for the Empulse the 10.0 pretty much demands 220v charging.

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